15 - 30 minutes
Lock button on iPhone 4 didn't work
The guides worked perfectly! Took me about one hour. The magnetic project mat was great since the parts was small.
I didn't have to replace the power button itself - its in metal and was not broken. The problem was the sensor cable where the switch was attached. The phone worked flawlessly after the repair!
Magnetic Project Mat
iPhone 4 and 4S Power and Lock Button
iPhone 4 Power and Sensor Cable (GSM/AT&T)